This invention relates to electronic thermostatic controls, such as for controlling automotive air conditioning systems and like applications, and in particular to such thermostatic controls which sense engine power demands and the state of the evaporator fan in addition to temperature.
Solid state temperature control means are known in the art. For example, Speaker, U.S. Pat. No. 3,544,849, issued Dec. 1, 1970, discloses such a control means. The circuits there disclosed, however, have a very narrow temperature differential, and are very sensitive to component tolerance variations due to the delicate electronic balancing of the differential circuit. Improvements are thus necessary in order to make such a circuit amenable to broader applications.